<template>
  <div>
    <router-link  class="header-abs" tag="div" to="/" v-show="showAbs">
      <span class="iconfont header-abs-back">&#xe624;</span>
    </router-link>
    <div class="header-fixed" v-show="!showAbs" :style="opacityStyle">
      <router-link to="/">
        <div class="iconfont header-fixed-back">&#xe624;</div>
      </router-link>
      景点详情
    </div>
  </div>
</template>
<script>
export default {
  name: 'DetailHeader',
  data () {
    return {
      showAbs: true,
      opacityStyle: {
        opacity: 0
      }
    }
  },
  methods: {
    handleScroll () {
      const top = document.documentElement.scrollTop
      if (top > 60) {
        this.showAbs = false
        this.opacityStyle.opacity = (top - 60) / 140 > 1 ? 1 : (top - 60) / 140
      } else {
        this.showAbs = true
      }
    }
  },
  activated () {
    window.addEventListener('scroll', this.handleScroll)
  },
  deactivated () {
    window.removeEventListener('scroll', this.handleScroll)
  }
}
</script>
<style lang="stylus" scoped>
@import '~styles/varibles'
.header-abs
  position absolute
  left .2rem
  top .2rem
  width .8rem
  height .8rem
  line-height .8rem
  border-radius 50%
  background #000
  text-align center
  .header-abs-back
    color #fff
.header-fixed
  z-index 2
  text-align center
  line-height $headerHeight
  background $bgColor
  color #ffffff
  font-size .32rem
  position fixed
  top 0
  left 0
  right 0
  .header-fixed-back
    position absolute
    width .64rem
    text-align center
    left 0
    bottom 0
    color #fff
    font-size .4rem
</style>
